fix potential memory leak

use delete before return

Change-Id: I5449ad90bb6910f057bd825b722c9803a7343c34
Leak in ToneGenerator_native_setup

Failure in ToneGenerator::isInit causes a leak.
lpToneGen should be deleted.

Change-Id: I48df7a328fed01be8412d5449ee0753dad3c101f
StringBlock_nativeCreate: Possible Leak

osb can be leaked when osb->getError() != NO_ERROR

Change-Id: Icbeb8eb3fb78849c043fe032cc8f7050da041042